The present invention relates to a motor driving device and a motor system, and relates to technology for driving a three-phase motor by a sine wave as an example.
For example, Patent Literature 1 discloses a system to calculate the phase of a drive voltage of a motor based on an arithmetic expression that employs an angular frequency, a drive current value, and characteristic constants (a torque constant and an impedance value) of the motor. Patent Literature 2 discloses a system to select one of the phase of aback electromotive force and the phase of a drive current and to control the energization timing of a motor.
(Patent Literature 1) Japanese Unexamined Patent Application Publication No. 2010-288396
(Patent Literature 2) Japanese Unexamined Patent Application Publication No. 2005-102447